Calculation of benefits of floodwater utilization in the middle and lower reaches of Weihe River

The shortage precipitation in the middle and lower reaches of the Weihe River and its nonuniformity in space-time location have caused frequent occurrence of flood and drought in recent years.This resulted in not only the shortage of total amount of water resource,but also some serious problems related with water quality,water distribution and water engineering.Accordingly,floodwater utilization plays an important part in environmental protection and economic development,and it will get benefits in many aspects such as sedimentation reduction,flood control and economic growth.In this paper,integrated benefits of floodwater utilization were calculated by sharing coefficient based on analysis of characteristics of channel deformation,flood loss criteria,dam building and land use.The results are obtained as follows.The greater the flood flux,the more the riverbed erosion.The sediment reduction benefit will be 6200×104 yuan per year by decreasing the sediment deposition,the flood control benefits will be 24618×104 yuan per year,including 1926×104 yuan in the middle reaches and 22692×104 yuan in the lower reaches.The economic benefits will be 7743×104 yuan per year,including 1194×104 yuan of breed aquatics and 6549×104 yuan of irrigated farming.All the above indicated that the total benefits of floodwater utilization in the middle and lower reaches of Weihe River can reach 38561×104 yuan per year.